I don't have anything to do with CSUDH but I'm in the same situation with needing to notify schools with my intent to enroll and I still haven't heard from all the schools I applied to. I called one of the schools and since I didn't need to send a deposit or anything to save my spot, they said to just send in my decision saying yes I accept your offer, and if I hear back from a different school and want to go there, just call them asap and let them know I won't be attending. It's better to be safe than sorry. If you wait and deny their acceptance and wait for other schools, you run the risk of not being accepted into those other ones and then you have nowhere to go at all. I hope everything works out!